Thermostatic circuit making and breaking device



A. ALBERT 1,741,599

THERMOS-TTIC CIRCUIT MAKING AND BREAKING DEVICE Filed April 50, 1927 Patented Dec. 31, 1929 UNITED STAT ALBERTO ALBERT, OF BARCELONA, SPAIN THERMOSTATIC CIRCUIT MAKING AND BREAKING DEVICE Application led April 30, 1927, Serial No. 188,021, and in Spain May 15, 1926.

The subject oit this invention is an automatically operating device for giving a warning of suddenchanges of temperature and also for giving a warning when the teinperature has slowly varied and reached a previously determined temperature.

In the iirst case the device according to the invention is adapted for use for cases ot fire and in the second for preventing accidents which might occur when the temperature oit a certain place exceeds a given number ot degrees.

One ot the advantages or" this apparat-us resides in its mode of operation which permits a construction to be adopted which is strong and rigid and not liable to be damaged.

The device according to the invention is also characterized by its sensitiveness which makes it enter into operation when needed with great rapidity without, on the other hand, causing the optical or acoustic alarm signal, which forms a part of it, to enter into action unnecessarily.

The operation or' this warning device is based upon the increase in length by expansion which metal rods undergowhen sub jected to heat and the greater or smaller degree or" rapidity with which such increase tali-es place according to the cross sectional area ot' 'the rods.

A form of the device according to the invention is described hereinafter and illustrated in the accon'ipanying drawing in which:

Figure 1 is a iront view ot the same and Figure 2 is a side view of Figure 1.

The apparatus essentially comprises a plate 1 of any material which is a poor conductor ot heat and electricity. This plate has form-ed at its ends lugs or projections 2 and 3 in which are mounted three rods 4t, 5 and 6 which are parallel with each other and run in the direction of length of the plate 1. These rods are secured at the lower part in the projection piece 3.

The central rod 5, of largerdiameter than the outer rods, carries at its upper part a support 6 or'the pivot 7 of a lever 8 and 9 having arms or' unequal length. The end of the shorter arm 9 of this lever is pivotally connected to the upper end of the rod l while the end of the other arm is adapted to inale contact with the point 10 in which the rod 6 terminates. The rods 4 and 5 are connected together electrically and the first of them is provided with a terminal 11 to which is connected one oi' the wires 12 othe electrical installation in which the apparatus and the acoustic or luminous signal are connected. f i

The other wire is attached to the terminal 13 which is connected electrically with the rod 6 which is connected with the support 14 carrying a screw 15 which is adapted to estabiish contact, in the manner hereinafter described, with a lever or projection 16 secured to the support 6.

Moreover, the end ot the rod 6 is screwthreaded over a certain length and terminates in a knob 17. The screwthreaded portion of this rod engages in a corresponding thread in the projection 3 so that by turning the knob the distance separating the point 10 from the lever 8 can be varied.

At the saine time the central rod 5 is cov ered with wire coiled around it, so as to increase the cross section of the said rod.

rhe operation of this apparatus is as follows:

Assuming that, in accordance with instruc-` tions which are necessary for the mounting and setting to work of the device, the latter is set to bring into operation the corresponding alarm signal in the case when the air which surrounds the device undergoes an unforeseen increase in temperature, for eX- ample an increase ot 5O or else slowly increases in temperature to exceed It the air surrounding the apparatus slowly increases in temperature the rods 4; and 6 eX- pand and consequently increasein length; but as under these conditions the central rod 5 also expands in this way contact between the lever 8 and the point 1() cannot be established and if under these conditions the tem peratu're continues to increase, but slowly as stated above, there comes a moment when it exceeds the said 70o and the increase in length ot all the rods becomes such that the part or projection 16 of the support 6 makes i,

contact with the screw l5 and thus produces the operation of the alarm signal.

If on the other hand the increase in temperature is sudden the increase in length of the rods 4 and 6 is rapid on account of their small cross section, so that under these nen7 conditions as the central rod 5 does not increase in length so rapidly, the lever 8 is caused to be swung by relative movement between the rods 4 and 5, and makes Contact with the point l0 to close the circuit of the said alarm signal.

The constructional details of the apparatus described may be varied asrega-rd dimensions and the shapes of the parts and the materials oi" which the latter are made7 the method ot covering or protecting the same which is adopted, and the means for suspending or securing it may also be varied and in general 2O all modifications may be made which do not alter, change or modify the-essential nature of the invention.

l/Vhat I claim is l. A thermostatic circuit making and breaking device comprising a mounting which is a non-conductor oi' heat and electricity, a central rod on said mounting` and tWo other rods, one on either side of said central rod, of smaller diameter than the central rod, the lower end of each of said rods being secured to the mounting, a support at the upper end of the central rod, a lever pivotally mounted at an intermediate point along its length on said support, the end or" one arm of said lever being pivotally connected to the upper or free end o1" one of the outer rods, a point on the upper or free end or the second louter rod, which is adapted to make electric contact With the free end of the lever to close an electric circuit When a sudden rise in temperature takes place, a second contact connected With the second outer rod and adapted to make electric Contact with the lever support to close the electric circuit in the event of a gradual rise to a dangerous temperature.

2. A thermostatic circuit making and breaking device according to cla-im l, in which the two contacts are each adjustable in position.

3. A thermostatic circuit making? and breaking device according to claim l, in which the central rod is completely surrounded by a covering` of Wire so as to in- Cil V crease the cross-section of said rod.

In testimony whereof I have signed my name to this specification.

ALBERTO ALBERT. 

